Heretofore, there have been proposed various exposure apparatus, as an example of recording apparatus, having a spatial light modulator such as a digital micromirror device (DMD) or the like for exposing a recording medium to an image with a light beam modulated with image data. The DMD is a mirror device comprising a number of micromirrors for changing the angles of their reflecting surfaces depending on control signals based on image data, the micromirrors being arranged in a two-dimensional array on a semiconductor substrate such as of silicon or the like. An exposure head with such a DMD is relatively moved in a scanning direction over a recording medium to record a two-dimensional image thereon by way of exposure.
In order to increase the resolution of the image recorded on the recording medium, there has been proposed an exposure apparatus in which a DMD comprising a two-dimensional matrix of micromirrors is inclined to the scanning direction, so that the exposed points formed on the recording medium by closely located micromirrors partially overlap each other (see Japanese Laid-Open Patent Publication No. 2001-500628 (PCT)). When a plurality of exposed points are overlappingly formed on the recording medium by way of multiple exposure, it is possible to reduce an image quality degradation which tends to be caused by a defect of an optical system such as microlenses corresponding to the micromirrors, a defect of the micromirrors themselves, or an amount-of-light irregularity of light beams reflected by the micromirrors to the recording medium.